ATI OB – Peds Study Guide 1

OB

1. The menstrual cycle (Hypothalamic-Pituitary cycle)- from PowerPoint

a. Results from a functional hypothalamic-pituitary-ovarian axis and a

precise sequencingof hormones that lead to ovulation.

b. End of the menstrual cycle- estrogen and progesterone decrease

c. Hypothalamus is stimulated and secrete GnRH which stimulate anterior

pituitary gland tosecrete FSH which stimulates development of ovarian

Graafian follicles which produce estrogen

d. Estrogen level decreases

e. GnRH stimulate the anterior pituitary gland to release LH (day 12)

expels the ovum (24to 36 hours) No fertilization regression of the corpus

luteum

f. Progesterone and estrogen decrease menstruation

2. Fertilization and implantation of the fertilized ova- from PowerPoint

a. Fertilization

i. Fertilization occurs in the ampulla (outer third) of the fallopian tube

ii. Zona pellucida- zone reaction; no other sperm can penetrate the

fertilized egg

iii. Mitosis/cellular replication-zygote travels down the fallopian

tube and embedsinto the uterus (3-4 days)

iv. Rapid cellular division; implantation occurs 7-10 days post

conception

v. Mitosis/cleavage- 4 cleavage; 16 cleavage

vi. Morula- solid ball of 16 cells (72 hrs implantation in the fallopian

tube)

vii. Blastocyst- inner cell mass from the embryo and amnion

1. Implant in the upper uterine wall- rich blood supply;

strong musclefibers; thick lining

viii. Trophoblast- outer cell mass from the chorion and placenta

b. Implantation

i. Contact between growing structure, uterine endometrium, occurs

8-10 days afterfertilization

ii. Blastocyst embeds in the endometrium (6-10 days post conception)

iii. Can have implantation bleeding

iv. Development of the chorionic villi

v. Endometrium is known as the decidua

1. Decidua basalis, decidua capsularis, and decidua vera

3. Diagnosis of pregnancy: presumptive signs, probable signs and positive

signs (know thedifferences)

a. Presumptive signs- those that a mother can perceive (most obvious

is absence ofmenstruation) (**= on PowerPoint)

i. Fatigue (12 weeks)**

ii. Breast tenderness (3-4 weeks)- body changes**

iii. Nausea and vomiting (4-14 weeks)**

iv. Amenorrhea (4 weeks)- absence of menstruation**

v. Urinary frequency (6-12 weeks)

vi. Hyperpigmentation of skin (16 weeks)

vii. Fetal movements (quickening; 16-20 weeks)

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viii. Uterine enlargement (7-12 weeks)

ix. Breast enlargement (6 weeks)

b. Probable signs- those that can detected on physical examination by

a health careprovider

i. Cervical changes**

ii. Braxton hicks contractions (16-28 weeks)

iii. Positive pregnancy test (4-12 weeks)**

iv. Abdominal enlargement (14 weeks)

v. Ballottement (16-28 weeks)- examiner pushes against the women’s

cervix duringa pelvic examination and feels a rebound from the

floating fetus

vi. Goodell’s sign (5 weeks)- softening of the cervix **

vii. Chadwick’s sign (6-8 weeks)- bluish purple coloration of the

vaginal mucosaand cervix and leukorrhea- vaginal changes **

viii. Hegar’s sign (6-12 weeks)- softening of the lower uterine segment

or isthmus

**

c. Positive signs- these signs confirm that a fetus is growing in the uterus ,

visualizing thefetus by ultrasound, palpating for fetal movements, and

hearing a fetal heartbeat

i. Ultrasound verification of embryo or fetus (4-6 weeks)-

visualization**

ii. Fetal movement felt by experienced clinician (20 weeks)**

iii. Auscultation of fetal heart tones via Doppler (10-12 weeks)

iv. Fetal heart separate from mother’s **

4. Know the difference between the Hegar, Goodell, & Chadwick’s signs (how are

they assessed)

a. Hegar sign- uterine isthmus will be softened

b. Goodell sign- cervix will be softened

c. Chadwick’s sign- bluish coloration of the cervix and vaginal mucosa

5. Endocrine function: Review the slides on Pregnancy tests (confirmation of

pregnancy)

a. Serum and urinary pregnancy tests are performed

i. hCG is the earliest biological maker (production begins as early as

implantation)

ii. Detection 7-10 days after conception, level peaks 60-70 days than

declines

iii. Higher level is indicative of fetal abnormality or multiple gestation

iv. Slow to increase/low level is indicative of potential

miscarriage or ectopicpregnancy

6. Know the functions of estrogen and progesterone in relationship to the pregnancy

a. Estrogen- secreted by the ovaries and is crucial for the development and

maturation of thefollicle.

i. Is predominant at the end of the proliferative phase, directly

preceding ovulation.After ovulation, estrogen levels drop sharply

as progesterone dominates.

ii. In the endometrial cycle, estrogen induces proliferation of the

endometrial glands. Estrogen also causes the uterus to increase in

size and weight because ofincreased glycogen, amino acids,

electrolytes, and water. Blood supply is expanded as well

b. Progesterone- secreted by the corpus luteum, progesterone levels

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increase just beforeovulation and peak 5 to 7 days after ovulation.

i. During luteal phase, progesterone induces swelling and increased

secretion of theendometrium. This hormone is often called the

hormone of pregnancy because ofits calming effect (reduces

uterine contractions) on the uterus, allowing pregnancy to be

maintained.

7. Terms related to pregnancy: GTPALM

a. G- gravida

b. T- term pregnancies

c. P- preterm pregnancies

d. A- abortions

e. L- living children

f. M- multiple gestations and births

8. Measurement of the pregnant uterus – fundal height

a. Fundal height is the distance (in cm) measured with a tape measure from

the top of the pubic bone to the top of the uterus (fundus) with the client

lying on her back with her knees slightly flexed. Fundal height typically

increases as the pregnancy progresses; it reflected fetal growth and

provides a gross estimate of the duration of the pregnancy. Fundal

measurement should approximately equal the number of weeks of

gestation untilweek 36.

9. Physiological changes in pregnancy- from powerpoint

a. Reproductive system adaptations (from powerpoint)

i. Uterus

1. Estrogen: causes changes in size, shape and position (Wt

increases from70 gm to 1,200 gm)

2. Large increase in blood flow- blood vessels elongate,

enlarge, sprout newvessels and dilate (diameter of the

uterine artery double in size)

3. Uterine contractility- Braxton hicks

4. Formation of the lower uterine segment (6-8 weeks of

gestation)

5. Change in shape

a. 3 months- pelvic cavity

b. 20 weeks- level of umbilicus

c. 36 weeks xyphoid process (highest level)

d. Monthly measurement corresponds w/ number

of gestationweeks

ii. Cervix

1. Goodell’s sign- 6-8 weeks cervix softens

2. Progesterone- formation of mucus plug

3. Chadwicks- increased vasculation

4. 4 weeks before birth- cervical effacement and cervical

ripening

iii. Vagina

1. Increased estrogen- increased vascularity and hypertrophy

2. Thickening of the vaginal mucosa

3. Leukorrhea

4. Increased acidity

iv. Ovaries

1. Increased blood supply- enlargement 12-14 weeks

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2. Cessation of ovulation

3. Week 6-7 of pregnancy- ovaries active

4. After 8 weeks- placenta takes over to production of

progesterone

v. Breasts

1. Influence of estrogen and progesterone- larger and tender

2. Highly vascular- increased blood supply

3. Larger nipples; aerolar deeper pigmented

4. Stria

5. Prominent Montgomery tubercles (sebaceous glands)

6. 3rd trimester- colostrum

7. Lactiferous ducts

b. General body system adaptations (from powerpoint)

i. Gastrointestinal system

1. Early- nausea and vomiting (morning sickness)

2. Changes in taste; pica (food craving) can be sign of iron

deficiency

3. Pyrosis (heart burn)

4. Gum hypertrophy

5. Ptyalism (excessive saliva)

6. Constipation and hemmorrhoids

ii. Neurologic system

1. Carpel tunnel syndrome (last trimester)

iii. Cardiovascular system

1. Cardiac hypertrophy, increased blood volume

2. Increase in pulse (10-15 b/m) 14-16 weeks

3. Disturbance of the cardiac rhythm

4. Blood volume

a. Approx. 1500 ml increase (40-50%) above prepregnancy state

b. Begins 10-12 weeks peaks 32-34 weeks

c. Accelerated production of RBC- 20-30%

d. Decrease in Hb (more noticeable in 2nd trimester)

e. Physiologic anemia

f. WBC increase

5. Cardiac output

a. Increases from 30-50% by 32 weeks and

declines to 20%increase by term

b. Supine position and large uterus impedes venous

return andlowers BP

c. Increased risk of blood clotting

6. BP

a. Systolic usually remain the same as prepregnancy but maydecrease slightly as the

pregnancy advances

b. Diastolic 1st trimester- begin to decrease

i. 24-32 weeks continues to fall

ii. Gradually increase

iii. Term- return it pre-pregnancy

iv. Supine hypertension syndrome

iv. Respiratory system

1. Increased chest expansion

2. Displacement of the diaphragm (up to 4 cm), engorged

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